the whole concept of heresy & heretics assumes that there is a majority defining a minority as such; never in history a majority has been defined as heretic, or at least not in the long term: once a current of thought becomes majority, it ceases to be heretic. So, time will tell: I am pretty sure that, if the camera will be working properly and if MF/AF is well implemented, the new Fuji will be a success and (relatively to the niche it is directed to) hugely popular. That said, in this forum of course Leica users will always be a majority, so a Fuji user (even with M glass) will be considered heretic; however, will M-body users still be a majority of the total RF-style camera user base? I am not sure, too many unpredictable variables to be able to tell now.

What I can say, personally speaking, is this:

IF the camera will be working properly;

IF the lenses will deliver;

IF AF/MF will be implemented intelligently;

IF the use of adapted lenses will be implemented intelligently;

THEN

I will get the complete set of camera & three lenses;

I'll keep my Noctilux f1 for the wonderful results it provides;

I'll sell my M9 & other M lenses, except -->

I'll keep a M film body, just because I love to shoot film, with a 35 lux and the Nocti.

What the Fuji offers that the M9 doesn't? (note: all this is on paper at the moment, but let's talk assuming all will be working as per specs)

Variable magnification VF;

better sensor, better control of Moire;

much better low light performance;

better WA results, due to the design of the lens mount, distance to sensor plane, etc;

incredibly easier use of longer lenses (with the EVF option): think a 90 or 135 M adapted, for a 135 or 200 FOV, without having to frame & focus in the minimal patch of the M9's VF;

possibility of using MF & AF lenses according to different situations;

Note that I am comparing it with the M9; if I still had the M8, that would definitely be a no-brainer (still, assuming that all will work well with the new Fuji).

Now, if you shoot all day with a 15mm or 12mm on the M9, then you'll not have any lens of comparable FL; on the other hand, though, the use of longer lenses will be enormously easier. If you love the M way of focussing and framing, then you'll not find it on the new Fuji, at least not exactly the same; however, from what I saw I think that the using the OVF you'll have empty framing around the actual image to foresee the action, while being able to frame DSLR-like with the EVF...

So - not exactly two alternative cameras, but close enough; a good choice for people to have, so one can decide which features he wants/needs most and buy the camera that offers them, and still be able to use M glass on both.